What are the operating points for a bipolar transistor used as a switch?

When a bipolar junction transistor (BJT) is used as an electronic switch, it is driven between two extreme states to act like a physical switch being either fully closed or fully open. The fully 'on' state is called saturation, where maximum current flows from the collector to the emitter. The fully 'off' state is called cutoff, where practically no current flows. The active region, located between cutoff and saturation, is used for linear signal amplification, not switching. Distractors like 'enhancement and depletion modes' are terms specifically used to describe Field Effect Transistors (FETs), not bipolar transistors.